Insert for footwear midsole

ABSTRACT

An insert for a footwear midsole has a center portion which extends centrally across the midsole, a medial portion which extends upwardly from the center portion at the inner side of the midsole and a lateral portion which extends upwardly from the center portion at the outer side of the midsole. In a preferred embodiment, the insert is made from a cork rubber material and portions of the medial and lateral portions extend above the outsole and overly the upper of the footwear where they are exposed.

BACKGROUND OF THE INVENTION

It is well known to selectively stiffen the sole of footwear by placinga stiffer insert in a portion of the midsole. Doing this providesstability, allows the midsole to bend at the desired location and allowsthe remainder of the midsole to be made more flexible and cushioningthan it otherwise could be. A common material used for such an insert ismetal. However, prior art inserts do little to provide tortionalstability since tortional movement of the foot is generally above thetop of the midsole. In addition, if the insert is metal the portion ofthe midsole containing the insert is substantially not flexible at all.Finally, if the insert is metal, it activates airport metal dectors ifthe user forgets to remove the footwear before passing through them.

BRIEF SUMMARY OF THE INVENTION

The subject invention provides a midsole insert having medial andlateral portions which extend upwardly from a center portion whichprovides both longitudinal and tortional stability in the midsole it isplaced into.

The foregoing and other objectives, features, and advantages of theinvention will be more readily understood upon consideration of thefollowing detailed description of the invention, taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a first side elevation view of a shoe having an insert of thesubject invention placed in it.

FIG. 2 is the opposite side elevation view of the shoe of FIG. 1.

FIG. 3 is a plan view, partially broken away to show hidden detail of afootwear midsole with the insert of the subject invention in it.

FIG. 4 is a sectional view taken on the line 4-4 in FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring now to the drawings, a shoe 10 has a midsole 12, an outsole 14and an upper 16 which are all joined together in the conventionalfashion. An inner sole 18 is inserted inside of the shoe above themidsole, FIG. 4. The midsole 12 is made from a material that is flexibleand provides good cushioning for the foot. A typical material used forthis purpose is molded ethylene vinyl acetate (“EVA”). A cavity 20 isformed in the upper surface 22 and the opposed side surfaces of theinsole. Referring to FIG. 3, the back end 24 of the cavity 20 is shownin the embodiment illustrated as extending from the inside edge of themidsole laterally across the midsole proximate the front of the heel 26and then extending rearwardly to near the back of the heel at theoutside edge of the midsole. The front end 28 of the cavity 20 is shownas extending transversely across the midsole from near the ball of thefoot at the inside of the midsole to approximately the middle of thearch at the outside of the midsole. However, the exact location andextent of the cavity 20 can vary depending on the application.

Located in the cavity 20 is an insert 30. The insert 30 has a centerportion 32 which fills the portion of the cavity located in the uppersurface 22 of the midsole. Thus, the insert causes no significantdiscontinuity in the upper surface of the midsole. Located at the insideedge of the center portion 32 is a medial portion 34. The medial portionextends upwardly from the center portion and fills the portion of thecavity 20 located in the inside edge of the midsole. Located at theoutside edge of the center portion 32 is a lateral portion 36. Thelateral portion extends upwardly from the center portion and fills theportion of the cavity 20 located in the outside edge of the midsole. Themedial and lateral portions of the insert extend above the outsole andoverlay the outside surface of the upper 16. In addition, the outsole 14extends downwardly at the medial and lateral portions of the insertexposing even more of them. For aesthetic reasons the upper edges of themedial and lateral portions of the insert and the downwardly extendingportions of the outsole are curved. The insert is made from a materialwhich is stiffer than the midsole material. In a preferred embodiment,the insole is made from a combination of EVA and cork rubber. Thiscombination gives a cork appearance to the material which results in theexposed portions of the medial and lateral portions also being a designelement.

The insert 30 provides additional stiffness to the midsole 22 at thelocation where additional stiffness is required, essentially under theball of the foot. As a result, the rest of the midsole can be moreflexible and have greater cushioning than otherwise would be possible.However, unlike metal inserts, the use of an EVA/cork insert stillallows some flexibility along the entire extent of the midsole.Moreover, due to the fact that the front edge of the insert extendsdiagonally across the midsole, the midsole flexes approximately at thebase of the toes, rather than at the arch. In addition, by not having ametal insert, footwear utilizing the subject midsole do not triggerairport metal detectors.

By having the insert extend upwardly along both sides of the midsole, italso provides tortional stability. This prevents the foot from rollingside-to-side while walking which causes discomfort and can cause ankleinjury. In addition, it tends to reduce over pronation or supination ofthe wearer's feet.

Finally, by making the insert from a cork material and extending themedial and lateral portions 34, 36 above the outer sole 14 onto theupper 16 where they are exposed, the inserts provide an aestheticallypleasing design feature.

The terms and expressions which have been employed in the foregoingspecification are used therein as terms of description and not oflimitation, and there is no intention, in the use of such terms andexpressions, of excluding equivalents of the features shown anddescribed or portions thereof, it being recognized that the scope of theinvention is defined and limited only by the claims which follow.

1. An insert for footwear having a midsole, an outsole and an upper,said insert comprising: (a) a center portion which extends across themidsole; (b) a medial portion which extends upwardly from the centerportion at the inner side of the midsole; and (c) a lateral portionwhich extends upwardly from the center portion at the outer side of themidsole.
 2. The insert of claim 1 wherein said medial portion is locatedgenerally forwardly of said lateral portion.
 3. The insert of claim 1wherein at least portions of said medial and lateral portions extendabove the outsole and over exposed portions of the upper.
 4. The insertof claim 1 wherein said insert is a unitary molded element.
 5. Theinsert of claim 1 wherein said insert is embedded in said midsole. 6.The insert of claim 1 wherein said insert is stiffer than said midsole.7. The insert of claim 1 wherein said insert is made from a combinationof ethylene vinyl acetate and cork.
 8. The insert of claim 1 whereinsaid center portion is located immediately in front of a heel portion ofsaid midsole.
 9. The insert of claim 8 wherein said lateral portionextends partially over said heel portion.
 10. The insert of claim 5wherein said insert is located in a cavity formed in a top surface ofsaid midsole.
 11. The insert of claim 3 wherein the portions of saidlateral and medial portions which are exposed have arcuate upper edges.